Subsubsection Elbow Fittings
A pipe elbow is a fitting used to join two sections of straight pipes at an angle.
Standard elbows are available in 90° , 45° and less commonly 22.5° angles. A 90° Ell is also called a quarter-bend.
Standard elbows fit the same size pipe and female threads on both ends. When one end is smaller than the other the fitting is called a reducing elbow (h), and when one end has male threads the fitting is called a street elbow (i).
Short radius elbows have a radius of curvature of about one pipe diameter from center of the bend to the center of the elbow face, while the radius of curvature for long radius elbows is about one and a half diameters. Long radius elbows produce less turbulence in the fluid which results in reduced frictional losses and pressure drop, but they take up more room and are more expensive.
